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The topic of non-redundant near-field sampling has received much attention in recent literature. However, a practical implementation has so far been elusive. This paper describes a first step toward such a practical implementation, where the practicality and generality are maximized at the expense of more acquired data points. Building on the theoretical work of faculty at the University of Salerno...
V-band (50–75GHz) applications such as 5G and myriad others are the catalyst for high performance near-field antenna measurement systems. For Spherical Near-Field (SNF), the traditional approaches at millimeter wave frequencies collect two full spheres of data in the near-field where each sphere samples one of two linear and orthogonal fields of the antenna under test (AUT). These two orthogonal polarizations...
In this paper, we explore the possibility of using a photonics-based E-field sensor as a near-field probe. Relative to open-ended waveguide (OEWG) probes, a photonics probe could offer substantially larger bandwidths. In addition, since it outputs an optical signal, a photonics probe can offer signal transport through optical fiber with much lower loss than what can be achieved using RF cables. We...
We are developing a fundamentally new atom-based approach for electric (E) field metrology. This technique has the capability of becoming a new international standard for E-field measurements and calibrations. Since this new approach is based on atomic transitions of alkali atoms (mainly caesium and rubidium atoms), the probe is self-calibrating and has a capability of performing measurements over...
Dual-polarized probes with wide-bandwidth operational capabilities are highly desirable for time-efficient Planar Near-Field (PNF) measurements [1]-[3]. However, sometimes the performance tradeoffs necessary to achieve the desired operating bandwidth make such probes impractical for many applications. Traditional probes are often bandwidth limited, and their electrical size can be an undesired source...
Spherical Near-Field (SNF) measurements are an established technique for the characterization of an Antenna Under Test (AUT). The normal sampling criterion follows the Nyquist theorem, taking equiangular samples. The sampling step size depends on the smallest sphere that, centered in the coordinate system of the measurement, encloses the AUT, i.e. the global minimum sphere. In addition, a local minimum...
The portable antenna measurement system PAMS was developed for arbitrary and irregular near-field scanning. The system utilizes a crane for positioning of the near-field probe. Inherent positioning inaccuracies of the crane mechanics are handled with precise knowledge of the probe location within the transformation algorithm. The probe position and orientation is tracked by a laser while the near-field...
The rise in the utilization of Unmanned Aerial Vehicles (UAVs) in the last years has also brought concerns in terms of Electromagnetic Compatibility (EMC) regulation of these platforms. Depending on the nature and operations of the UAVs, they are being required to go through the same processes than an aircraft EMC certification of aircraft involves a wide variety of tests. This paper deals with two...
Comparison activities in which a number of measurement facilities compare their measurements of the same antenna in a standard configuration have become important for documentation and validation of laboratory expertise and competence. It is also mandatory to have regular participation in such activities to obtain and maintain accreditations like ISO 17025. The main goal of the facility comparison...
Research in mm-wave has gained momentum in recent years and is requiring new laboratories and experimental methods. In this paper, a new mono- and bistatic radar cross section (RCS) facility operating at W-band frequencies is detailed. The mechanical system is capable of full target rotation and a large variation of the bistatic angle (25°-335°). It features exceptional precise alignment capabilities...
A novel low cost and high performance miniaturized broadband Additive Spiral Antenna (ASA) technology (patent pending) has been developed. Unlike other conventional spiral designs, this new spiral antenna leverages Additive Manufacturing (AM) 3D zig-zag shapes to achieve an efficient slow wave radiation structure for extending spiral's low frequency performance without size increases. Conversely,...
This paper presents the results of a recent study concerning the computational electromagnetic simulation of a spherical near-field (SNF) antenna test system in the presence of a compact antenna test range (CATR). The plane-wave scattering matrix approach [1, 2] allows many of the commonly encountered components within the range uncertainty budget, including range reflections, to be included within...
The accurate characterization of low-gain antennas at VHF frequencies is challenging. Such antennas can be tested outdoors for convenience or in very large and thus expensive indoor Far-Field (FF) ranges [1]. Indoor Near-Field (NF) systems are often considered a better cost compromise for such measurements, mainly due to the relaxed requirements on chamber size. However, reflectivity issues and other...
In this paper, a new method of matching coaxial ports of PCB mounted connectors utilizing a quarter-wavelength transformer on the PCB-sided port of the connector is presented. The possible localizations of the network are determined from theory and applied exemplarily on a 32K243 connector from Rosenberger. Measurements of the unmatched and matched SMA connector are compared.
Temperature changes cause thermal expansion of antenna materials and will have an important impact on antenna performances. In some applications, it is sufficient to calculate the antenna deformation by mechanical analysis and determine the RF impact by EM analysis tools. However, if the environmental conditions of the final antenna are stringent and considered critical as in the case of military...
Antennas installed in modern cars are often highly integrated. In such cases, the entire vehicle is contributing to the radiated field, in particular at lower frequencies such as VHF. The complete characterization of the full vehicle is thus typically required. For frequencies down to 70 MHz, a widely accepted and cost effective solution is a multi-probe spherical Near Field (NF) system in which the...
Automotive antenna measurements are increasingly demanding. Modern cars are equipped with a large number of integrated antennas, spanning a wide frequency range for a large number of applications. Integrated antennas are strongly coupled with the structure, final testing are thus performed on the vehicle to accurately determine the performance. The physical and electrical size of typical cars, impose...
The measured source or Huygens box antenna representation has become an increasing popular solution to create accurate computational models of measured source antennas for the numerical analysis of antenna placement on complex platforms such as satellites. The equivalent representation of the measured antenna is obtained through the equivalent current (EQC) or inverse source technique, which is a...
Current techniques for testing of aircraft radomes are time consuming, not as precise as desired, and requires dedicated far field test range, compact test range, or anechoic chamber, or other specific systems for measuring one or other of the parameters. To overcome all these limitations, and to obtain a unique system for a complete diagnosis, a novel technique of radome characterization is proposed...
This contribution demonstrates a method to measure the absolute Group Delay (GD) of a high gain dual feed offset reflector antenna for circular polarized signals in Ku- and S-band which reaches a measurement accuracy of better than 10 picoseconds. The demand for best possible accuracy determination of the GD arises from the fact, that the Antennas Under Test (AUTs) are part of microwave link, which...
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